portfolio project readme

openedx/features/portfolio_project/README.rst

+Portfolio Project
+-----------------
+
+This is the current home of the Portfolio Project feature.  This is not a fully
+supported feature.
+
+See `LEARNER-3515`_ for details.
+
+TODO: `LEARNER-3515`_: If this feature gets implemented, this directory should
+move to lms/djangoapps and out of openedx/features.
+
+.. _LEARNER-3515: https://openedx.atlassian.net/browse/LEARNER-3515